Conventionally, a liquid processing apparatus is known which performs various kinds of liquid processings on a processing target object such as, for example, a silicon wafer or a compound semiconductor wafer, using a processing liquid such as, for example, an alkali processing liquid or an acid processing liquid (see, e.g., Japanese Patent Laid-open Publication No. 2012-190823).
The liquid processing apparatus according to the related art includes a plurality of liquid processing units in which a liquid processing is performed, and is configured such that the exhaust gases from the plurality of liquid processing units are discharged all at once through a common exhaust path. Meanwhile, an exhaust mechanism such as, for example, a pump is connected to the common exhaust path, and an exhaust amount of the common exhaust path is maintained constant in order to suppress the pressure of each liquid processing unit from being fluctuated at a timing where a liquid processing is performed.